The Intermittent Fasting Omnibus: Myths Busted, Facts Revealed
Originally written by Alloran Intermittent fasting (hereafter IF) is the practice of intentionally abstaining from food and caloric beverages (water, unsweetened tea, and black coffee are all OK, and arguably diet sodas are as well) for a set amount of time, interspersed with periods of eating. You already fast for 6-8 hours every night when you sleep. IF builds on that, extending the time without food into your waking hours. This article will explore common questions about intermittent fasting and the science behind it. 'Are you starving yourself on purpose?' I wouldn't call it starving, and indeed, I think most people are too flippant with that word, calling themselves "starving" after missing a single meal. True starvation occurs when your body is so calorie depleted that it has burned all fat reserves except a tiny fraction, and has begun to consume your muscles in earnest, which quickly leads to death (your heart and diaphragm are among the muscles that are destroyed, and you can imagine where that would cause a problem). This does not occur in IF as it is commonly practiced, because in general the fasting periods are short (<36 hours) and they are interspersed with feeding periods where sufficient calories are consumed to prevent that sort of eventuality. 'How much hunger is really involved?' Significant feelings of hunger are going to be involved. However, it is very much controllable, and in my opinion, this element of battling and eventually mastering your hunger is among the most important and beneficial aspects of IF. I have no fear at this point of ever becoming overweight, because I am that confident of my control of my hunger. I know that I can cut down on my calorie intake as far as I want at any time. That is the power of IF. 'Is there a risk of anorexia?' No studies have been done on this that I know of, but I see no reason whatsoever why there would be. Intermittent fasting can be very successfully applied to bulking in order to minimize fat gain, and this is diametrically opposed to the disordered thinking of anorexia nervosa (summed up as: weight gain is the DEVIL!). IF is a tool as I see it, and it can be used for "good" (healthy body recomposition, whether that is increasing muscle or losing fat) or "evil" (dieting yourself to death). I would think that anorexics would generally used prolonged fasting rather than IF if they went that direction, but that's just my suspicion. 'How dangerous is this? I've heard it's bad to miss meals!' There are risks involved in everything we do. The question is: how we can minimize those risks, and do the benefits outweigh the risks? IF, done properly (minimizing risks), is not dangerous. This study concerns a 27 year old man who weighed 456 lb, and who, under close medical supervision, fasted for 382 days. His only food was a daily multivitamin, some small amounts of yeast (I have no idea, don't ask), and at some points some sodium and potassium supplements. He lost 276lbs and kept it off for 5 years, only gaining back 16lbs. His only issues during the period of the fast were some electrolyte disturbances that were controlled with the sodium and potassium supplements. This is an extreme example to show that even very extended fasting is not necessarily dangerous in people without any underlying diseases: http://pdfcast.org/pdf/382-day-fast The authors of that paper do note that five people have been recorded to die during extended fasts like this (this was in 1973, and these are only the scientifically recorded deaths), but all of them occurred following fasts of >13 days (several of them with prior disease conditions), and no extant IF program recommends fasting this long. As above, 36 hours is usually the maximum. Note: PLEASE do not try this sort of extended fasting (>36 hrs) at home. This is for illustrative purposes only, not at all recommended. It should go without saying that you need medical supervision to do something like this. Do not chance it, it is not worth it. IF works plenty well without taking this large a risk. For another perspective, consider our pre-agricultural ancestors, whose food was much more scarce than in modern times. If they all started croaking because they had to go without food for a day or two every so often, our race would have died out long ago. It makes logical sense that our bodies would be adapted to handle at least short periods of fasting, but what does the data say about all those things we've heard about missing meals? Let's take a look, shall we? 'Don't you lose mostly muscle and little fat when you fast?' No, this is exactly backwards, and it shows a profound misunderstanding of how our bodies handle various energy sources. Fat is a very high energy molecule for its weight compared to protein (>2x more energy dense), and though fat has many essential functions in our bodies, adipose tissue, which is the fat that is in storage beneath our skin has one primary purpose: to be an energy reservoir for when food is scarce. That's not to say it isn't involved in many complicated hormonal processes or to deny its insulation function, but energy storage is its primary purpose. The protein in muscles contains much less energy than fat, and it is more critical for our bodies to function (heart, diaphragm), and particularly for us to find food (skeletal muscle). In a typical 150lb man of average height, 85% of available calorie reserves are contained in fat stores. About 14% of available calories are in protein, and the remainder is glycogen (stored carbs). Clearly, fat is the primary energy storage molecule. From all this, it should be clear that from a physiological standpoint, it would make no sense for our bodies to go first to protein in a situation where there is no food to be had. By analogy, that would be like tearing apart tables, chairs, and ceiling rafters to build a fire when there's a perfectly good, massive stack of firewood sitting right outside the door. This is an imperfect analogy, because our bodies are always tearing up and rebuilding muscle to some degree even when we're well fed, and muscle catabolism is increased in fasting, but this increase is minimal compared to the vast increase in fat burning. The reason for this is that our bodies undergo a profound, but gradual hormonal change which begins when we stop eating and continues to develop until about 72 hours into a fast when it is maximal. These changes are designed to mobilize fat for energy production and to protect muscle from being consumed. Several things occur: Insulin decreases fairly dramatically, and glucagon rises. Glucagon entices your liver to both release stored carbs (which run out fairly quickly) and create new carbs from fats and proteins, and in addition it somewhat increases lipolysis (release of fats from storage into your blood), though this effect may be more due to decreased insulin than increased glucagon. Growth hormone also increases dramatically, and as we will see below, it protects muscle and encourages fat breakdown. Additionally, catecholamines like norepinephrine and epinephrine rise, and these raise your body's metabolism, at least temporarily in early fasting (see below under the metabolism section for more on this). Is there any science backing this up? *"Plasma glucagon concentrations rose twofold to a peak on the 3rd day of fasting and then declined *thereafter to a level maintained at or above postabsorptive. Insulin concentration declined to a plateau by the 3rd day. Thus a persisting altered relationship of glucagon and insulin concentrations characterized the fasted state." http://www.ncbi.nlm.nih.gov/pmc/articles/PMC322727/ *"It is concluded (a) that glucagon at high concentration is capable of stimulating lipolysis and ketogenesis in insulin-deficient diabetic man; (b) that insulin, mole for mole, has more antilipolytic activity in man than glucagon has lipolytic activity; and © that glucagon, on a molar basis, has greater stimulatory activity than insulin has inhibitory activity on hepatic glucose release." http://www.ncbi.nlm.nih.gov/pmc/articles/PMC301453/ *"Two days of fasting induced a 5-fold increase in the 24-h endogenous GH hormone production rate" http://jcem.endojournals.org/content/74/4/757.short *"These results demonstrate that GH—possibly by maintenance of circulating concentrations of free IGF-I—is a decisive component of protein conservation during fasting and provide evidence that the underlying mechanism involves a decrease in muscle protein breakdown." http://diabetes.diabetesjournals.org/content/50/1/96.short *"This supports the notion that stimulation of lipolysis is a primary and important effect of GH fasting." http://jcem.endojournals.org/content/94/11/4524. *"The rates of appearance (Ra) of glycerol and palmitic acid fat in plasma doubled from 12 h to 72 h of fasting (P < 0.01). Of the total increase in lipid kinetics, 60% occurred between 12 and 24 h of fasting; the greatest interval change occurred between 18 and 24 h of fasting." http://ajpendo.physiology.org/content/265/5/E801.short *"These findings suggest that these diets are equally as effective in decreasing body weight and fat mass, although intermittent CR category that includes IF may be more effective for the retention of lean mass calorie restriction alone." http://www.ncbi.nlm.nih.gov/pubmed/21410865?dopt=Abstract *Here is a discussion of the above article and its methodological strengths/weaknesses: http://www.leangains.com/2011/03/intermittent-fasting-for-weight-loss.html *"Previous studies suggest that while both fat and protein are lost during short-term fasting, protein loss is minimal and the majority of weight lost from muscle is primarily glycogen and water" If you look down at the graphs in the discussion, this study itself supports this conclusion as well- fat loss is about double the lean mass loss, and much of the lean mass loss is water in an 18hr fast in rats. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2919581/ And if all that techno-babble isn't your speed, just observe the profound "muscle loss" in these ladies and gents who do IF (mostly gents, but there are some ladies if you go back a page or two): http://www.leangains.com/search/label/Client%20results 'Doesn't it wreck your metabolism? ' No, it does not. According to the following study, your metabolism actually increases steadily up to about 60 hours into a fast, at which point, it begins to decline. This is seemingly brought about by increased catecholamines mentioned above. Intermittent fasting takes advantage of this very fact by limiting fasting to short intervals. *http://www.ajcn.org/content/71/6/1511.long 'Won't I get hypoglycemic? ' It's possible if you have a disease like Diabetes Mellitus or some other serious metabolic abnormality, but otherwise no. *"Adults, despite subjective signs of hypoglycemia, can fast without any metabolic or endocrine derangement." http://www.ncbi.nlm.nih.gov/pubmed/17522614 'How about working out? Won't this ruin your intensity and your GAINZ? ' Again, no. And there is some preliminary indication that the opposite may be true: *"Our results indicate that prior fasting may stimulate the intramyocellular anabolic response to ingestion of a carbohydrate/protein/leucine mixture following a heavy resistance training session." http://www.springerlink.com/content/w8712615714k8150/ *Here's some discussion of the above study: http://www.leangains.com/2009/12/fasted-training-boosts-muscle-growth.html *"Metabolic effects of an overnight fast (postabsorptive state, PA) or a 3.5-day fast (fasted state, F) were compared in eight healthy young men at rest and during exercise to exhaustion at 45% maximum O2 uptake. Lower carbohydrate utilization in the F state was accompanied by higher circulating fatty acids and ketone bodies, lower plasma insulin levels, and the maintenance of physical performance reflected by similar time to exhaustion." http://www.ncbi.nlm.nih.gov/pubmed/3292504 *"The psychosomatic sensation, physiologic, and metabolic data all indicated that endurance exercise for up to 90 min for fit individuals is not limited by a short-term fast or enhanced by carbohydrate supplementation." http://www.ncbi.nlm.nih.gov/pubmed/17489012 *"Eight young men were tested for strength, anaerobic capacity and aerobic endurance in a post absorptive state and after a 3.5 day fast. The 3.5 day fast did not influence isometric strength, anaerobic capacity or aerobic endurance. It was concluded that there are minimal impairments in physical performance parameters measured here as a result of a 3.5 day fast." http://www.ncbi.nlm.nih.gov/pubmed/3622486 'Regarding longer term endurance events while fasting' *"Nine male marathon runners were exercised to exhaustion to determine the effects of a 27-h fast on endurance performance. Each subject completed two exercise tests at the same treadmill speed (set at 70% maximal O2 uptake), one following a 27-h fast and one 3 h after a preexercise meal, in random order. Fasting caused a 44.7 +/- 5.8% (SE) decrease in endurance performance (P less than 0.01)." http://jap.physiology.org/content/63/6/2502.abstract *"To determine if prolonged fasting affects substrate utilization and endurance time, seven trained men exercised to exhaustion on a cycle ergometer at 50% maximum oxygen consumption (VO2max) in an overnight-fasted (PA) state and after a 36-h fast (F). ... F produced a significant decrement in exercise endurance time compared with the PA trial (88.9 +/- 18.3 vs. 144.4 +/- 22.6 min, F vs. PA, a 38% decrease)." http://jap.physiology.org/content/69/5/1849.abstract Take home point: fasted training is clearly detrimental if you are going for maximum endurance. These two studies suggest about a 40% decrement in maximum distance. On the other hand, if you're not going to utter exhaustion, and if it's less than 1.5 hours of running/cycling/swimming, you may not experience any performance decrease (see the other studies above). Still, if it were me, I'd probably not do endurance training fasted unless it were fairly submaximal work and less than 1 hr. 'I'm sure this will destroy my ability to function at work. I won't be able to think being so hungry! ' Mostly untrue, as we will see below. Personally, my job is very cerebral, and I've experienced no ill effects from fasting as often as 24 hrs every other day (otherwise known as Alternating Day Fasting) for 9 continuous weeks. Also, I drink no coffee or other stimulants of any kind. But if you just have to see the science: *"a sample of female subjects (N = 21) was tested on a number of measures of cognitive function after three levels of food deprivation (miss one meal, miss two meals or miss all food for 24 h prior to testing) and a condition in which they ate normally for 24 h prior to testing. There was found to be no significant effects of food deprivation on sustained attention, attentional focus, simple reaction time or immediate memory. However, performance on a low processing load tapping task was significantly poorer when the subjects were deprived of food for 24 h prior to testing" http://www.journalofpsychiatricresearch.com/article/0022-3956(95)00009-T/abstract *"Cognitive performance, activity, sleep, and mood are not adversely affected in healthy humans by 2 d of calorie-deprivation when the subjects and investigators are unaware of the calorie content of the treatments." http://www.ajcn.org/content/88/3/667.abstract *"This interventional trial demonstrates beneficial effects of caloric restriction on memory performance in healthy elderly subjects. Mechanisms underlying this improvement might include higher synaptic plasticity and stimulation of neurofacilitatory pathways in the brain because of improved insulin sensitivity and reduced inflammatory activity." http://www.pnas.org/content/early/2009/01/26/0808587106 There have been some negative cognitive effects shown from prolonged low calorie dieting, but it is unclear how well this applies to IF in particular, especially since IF need not be low calorie, and it can in fact be used for bulking. Even if it does apply to IF, it would be no different than any other low calorie diet. *"In one of a continuing series of studies, the cognitive performance of normal weight female dieters was compared on two sessions, 3 weeks apart. Those who reported themselves as being on a weight-reducing diet on only one of the two sessions displayed poorer vigilance performance, slower reaction times and poorer immediate recall of words when they were dieting. In contrast, performance on a low processing load tapping task was unaffected." http://www.ncbi.nlm.nih.gov/pubmed/8587997 *"Compared with nondieting subjects with low to moderate scores on the restraint factor of the DEBQ, subjects (n = 15) who reported that they were currently dieting to lose weight displayed impaired performance on a vigilance task and also tended to show poorer immediate memory and longer reaction times. Highly restrained eaters who were not dieting at the time of testing, on the whole, performed at an intermediate level on these tests. In contrast, the dieters tended to show the best performance on an undemanding finger tapping task, indicating that they were not slowed in their fine motor responses or lacking in motivation to carry out the tasks." http://www.ncbi.nlm.nih.gov/pubmed/8190760 So take this as you will. 'It must be bad for you somehow, I know it is! ' There have been no multi-year studies focusing on the health parameters of human IF'ers yet that I know of, so it's possible. But as things stand now, the health benefitsfrom even short-term IF look fairly attractive, though still quite tentative and in need of further research (some are from animal models): *Summary: Human trials of alternate day fasting show increased insulin sensitivity, increased HDL (good) cholesterol, decreased triglycerides, and there is even some evidence of decreased cancer incidence and better cancer outcomes in animals. More research is needed to investigate other possible effects. http://www.ncbi.nlm.nih.gov/pubmed/17616757 *"These findings suggest that adipose tissue parameters may play an important role in mediating the cardioprotective effects of ADF day fasting in obese humans." http://www.ncbi.nlm.nih.gov/pubmed/20300080 *"Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction attack and stroke." http://www.ncbi.nlm.nih.gov/pubmed/15741046 *From the full text of this article, which is unfortunately not free: "We tested two IF regimens, an alternate-day fasting and an every 2 days fasting in C. elegans—an organism that has been shown to be an excellent model system for ageing research—and found that they increased lifespan by 40.4% and 56.6%, respectively (Fig. 1a, b and Supplementary Table 1). Therefore, we used fasting every 2 days as the IF regimen. This IF regimen increased resistance to heat and oxidative stress (Fig. 1c), and markedly delayed the age-related physiological decline. As animals age, the locomotion activity and muscle integrity decrease, showing impairment of cellular functions. IF markedly suppressed the age-dependent decline in these activities (Fig. 1d and Supplementary Fig. 1), suggesting that ageing is delayed in C. elegans by the IF regimen established here." http://www.ncbi.nlm.nih.gov/pubmed/19079239 *I'm not saying that IF will help you survive a nuclear bomb, but.... http://www.ncbi.nlm.nih.gov/pubmed/6761903 Note: all of these which reference animal models should most definitely be taken with a large grain of salt. The applicability to humans has frequently been poor in the past, to put it mildly, but these results are exciting nonetheless. And lastly, here are some other fasting myths debunked by Martin Berkhan, with MOAR SCIENCE (some may overlap with the above), in case you have other questions I didn't answer:Top Ten Fasting Myths Debunked 'What are the best ways to approach IF?' IF is a very flexible method, and in some sense there are an infinity of ways to do it. There are however, some more popular ways to do it, and since IF is just now beginning to be understood and researched in humans, I think it's probably safer to follow one of these ways: *'Leangains '- Probably the most popular among those in the fitness community in my experience. This website is in a blog format and run by a guy named Martin Berkhan, who in my opinion is very scientifically minded and all about backing up most of what he says. If you want to get a general feel for what this method all about, use the guide I linked, or you can just browse some of his most popular articles. The draw of this method is that some people have actually claimed to be able to both gain muscle and lose fat at the same time by strictly following Martin's protocol. I haven't tried it personally except a day or two here or there, but I've met a lot of people that swear by it. The basic layout is fasting for 16 hours, followed by an 8 hour eating window, every day. You work out every other day, and carbs are cycled with high carbs on workout days and low carbs but higher fats on rest days. Higher calories on workout days, lower on rest days. He's all about the big 4 in the weight room, too. Martin Berkhan is on Fitocracy now! This is his profile: http://www.fitocracy.com/profile/Leangains/ The following are two variations on the Leangains theme by two of our own Fitocrats: *'Cheat Mode Diet' - devised by Silverhydra, give him a follow here: http://www.fitocracy.com/profile/Silverhydra/ *'RippedBody.jp' - from Andy Morgan, give him a follow here: http://www.fitocracy.com/profile/Andy-Morgan/ Both of these sites have a wealth of in-depth information, well worth spending time on if you are going to follow a Leangains style 16-8 split, or even if you're not. *'EatStopEat '- This links to an eBook by Brad Pilon, which is about $40. Expensive, and I know the website looks and sounds extremely scam-like, but there is no better source for broad scientific information on IF that I have found. I highly recommend it if you want more info on the science. My $40 was well spent, IMHO. His bibliography is massive, and I have found that in *most* all cases that I have checked, the sources he cites say exactly what says they do in the text. Brad's IF method is very simple and flexible, with fewer guidelines for diet and exercise than Martin's Leangains. In a nutshell, it is fasting for 24 hours, 1-2x /week, with no set schedule for which days. You just do it when its convenient. Brad advertises this more for weight loss than for body recomposition like Martin, but I see no reason why it can't be used for either or. Both Brad and Martin are responsible for introducing me to much (though not all) of the research I've presented here, and I wanted to give them credit specifically for all the hard work they've done to compile information about fasting. *'Fast 5' - this is one I'm not very familiar with, but have met some people who follow it. The basics as I know them are that you fast for 19 hours per day, and only eat during a 5 hour window. A more restrictive version of Leangains, at least on the surface of it. I am totally unsure of how they stack up as far as results. Martin seems to think it is too basic to be be very helpful. *'The Warrior Diet' - Another one I'm not that familiar with. I will defer to Martin Berkhan's review of it: "(20/4 hrs fast/feed). WD is actually not intermittent fasting in the strictest sense of the word, since the author allows small meals during the fast (vegetables, fruits). The WD book is somewhat of a cult classic, but the book prefers to quote stories and myth instead of scientifical evidence to supports its (sometimes ridiculous) claims." *'Experiments with Intermittent Fasting' Here is another eBook (free) that Kaylya alerted me to, which may be helpful. Another poster, Balbano, gives a short description for us: "A nice collection of thoughts about IF for people who are looking for something written by someone who is seemingly well respected and is not a 100% IF all the time type promoter (tl;dr John Berardi concludes that he likes IF). Because John Berardi has a big time diet coaching business with money to spend, the little ebook thing is well written, well designed and easy to read, which is always a bonus. He tests out a variety of IF protocols on himself, drops from 10% body fat to 4% body fat, concludes that he (personally) likes fasting 1 day per week, as well as the lean gains approach, but that he does not like fasting 2 days per week. He includes lots of notes about how the process went, as well as a full set of before and after bloodwork and some thoughts by doctor friends, as well as a nice conclusion about self-experimentation, and how and why you should do it. " *'http://artofmanliness.com/2012/01/25/intermittent-fasting/' Here is an article by Berardi, found by user Alfaj0r, that is sort of a very condensed version of the above eBook, could be a good introduction for people who ask you what the hell is up with you not eating. *'Alternating Day Fasting.' You may have noticed this term thrown around a lot in the research studies I linked above. It is easily the best studied of the intermittent fasting methods, but I've met very few who have attempted it. As I mentioned earlier, I did a variation of this method for 9 weeks where I would eat normally until dinner on Day #1, start fasting after dinner at about 6 PM, continue the fast until 6 PM on Day #2, then eat dinner, followed by eating normally until 6PM rolls around on Day #3. Rinse, repeat. Contra John Berardi's experience in the eBook just above, I didn't have any issues with either physical or psychological stress while doing this. I lost about 21 lbs on this diet, and I pretty much just ate to satisfaction during my feeding periods. I did calorie count for about a week in the middle of the 9 weeks just to see where I was at, found that I was at a reasonable calorie deficit, and then just stopped counting and continued to lose weight. Per my use of a caliper to measure body fat % at the beginning and end of this diet, the weight I lost was about 85% fat and 15% lean mass, which I think is pretty good, though I was starting at about 18% BF, so nowhere near lean. There is a book that lays this style out formally, but it sounds like it's 36 fasting/12 feeding, which is different from my method, and I've never read it: The Alternate-Day Diet 'Any tips on making this easier if I want to try it? ' I would say definitely start slowly. The "Experiments with Intermittent Fasting" eBook I linked above talks about doing a trial fast for 24 hours just to get a feel for what IF hunger really is like. I think that's a great idea, personally. You might even work up to it, like so: Day 1 - Eat normally up until dinner, and don't eat anything from dinner 'til bedtime. Eat breakfast the next morning at the usual time. Day 2 - Same, eat normally up until dinner, stop until bedtime, but then skip breakfast the next AM. Don't eat anything until lunch at noon-ish. Day 3 - Same, except skip breakfast and lunch the next AM and don't eat until dinner. If you don't eat dinner until you started fasting the previous day, then BAM!! 24 hour fast accomplished. Also, this is just a little "mind hack" that I find works very well for me, and others have said it's helpful too: instead of dreading your hunger pangs, redirect them. Convince yourself that the feeling of hunger is actually the feeling of fat burning off your belly. If you talk yourself into it enough, the hunger will actually start to feel like kind of a burning sensation. And actually, this little "lie" is almost true... 'Is there any reason somebody shouldn't do IF even if they want to? ' It's hard to say. Most of the studies of fasting have been with healthy volunteers. I personally suspect it could cause problems for diabetics or people with other metabolic disorders. I would be cautious about it and if you have any health problems that even *slightly* worry you in this regard, consult with your doctor. Your doctor may never have heard of IF, but he or she probably has dealt with people who fast for religious reasons, and so may have some good insight from that. For example, all Muslims the world over above a certain age are required to fast from sunup to sundown in the month of Ramadan, obviously in addition to fasting while sleeping, so their time to eat is markedly reduced. In some ways this might be considered intermittent fasting for a month. The only people exempt from this are the elderly, the chronically or acutely ill, diabetics, and nursing or pregnant women. Also, fasting could potentially interfere with the absorption, metabolism, or excretion of some drugs you are taking, so again, a doctor's advice will be helpful. Be smart about it, and exercise an abundance of caution. As Silverhydra has pointed out, all of the studies on IF (to my knowledge) have been done in adults. It's unclear how fasting affects people who are not fully physically matured, and it may be detrimental for normal development. So I'd say hold off if you are under 21 (though the exact age is very much arguable, and probably different for different people). It could be argued that it should be held off even later, since brain development continues into the late 20's, early 30's. Ultimately I think it will also depend on how you use IF: if you're eating a calorie surplus and using it to bulk cleanly, then probably less risky. If you're using IF to create a large calorie deficit for cutting/weight loss, and potentially not getting enough nutrients, could be a bigger problem. 'Do the benefits really outweigh the risks? ' That's something to decide for yourself. I think they do in my case, and so I use it. Do your own research and don't just rely on what you've seen here. This guide is just a stepping stone, not a destination. There will always be more to learn, and future discoveries may change my mind.